Behavior of composite steel -concrete beams with web openings

Dissertant

Hadi, Walid Khalid

Thesis advisor

Hammudi, May J.

University

University of Technology

Faculty

-

Department

Department of Building and Construction Engineering

University Country

Iraq

Degree

Ph.D.

Degree Date

2010

English Abstract

A composite beam is the accumulation of different materials so as to form a single unit in order to exploit the prominent quality of these materials according to their position within the cross-section of the composite beam.

The present study is aiming to investigate the structural behavior of simply supported composite beams, in which a concrete slab is connected together with steel I-beam by means of headed stud shear connectors.

The beams have been studied under the presence of web openings the study consists of two parts.

The first part is the experimental work in which six composite beams with constant degree of interaction were tested under central concentrated static load.

One beam is constructed without any web opening while the others contain various number, locations and shapes of openings.

Deflections at Missan and at ends of each opening were observed versus load.

For the present work, the experimental work includes also three push-out tests.

The aim of these tests is, firstly, to investigate the behavior and capacity of the stud shear connectors used to connect concrete and steel components in the tested beams, and secondly to represent its behavior by a mathematical model to be incorporated in the finite element model that predicts the structural behavior.

The experimental results show that the web openings decrease the strength of composite beams in the range of 19 % to 24 % for the tested specimens.

Distinctive effects for the location, number and shape of openings took place after initiation of section yielding.

Different patterns of cracks were observed.

In the second part, nonlinear finite element analysis was carried out to evaluate the behavior and strength of the tested composite beams utilizing the package software program (ANSYS V 11.0).

In the finite element model, concrete was simulated by eight-node isoperimetric brick elements (SOLID 65) in which steel reinforcing bars were modeled to be imbedded in the concrete element.

Plastic shell element (SHELL 43) was used to represent the steel beam element.

The steel-concrete interface was modeled by one dimensional nonlinear spring (COMBIN 39) presented at the location of each stud shear connector.

The results of the finite element model show good agreement with the test results.

The difference in ultimate load was ranges between (1 %-5 %) except for beam CB2 which was 12 %.

Parametric studies were carried out to investigate the effect of opening depth and width on the behavior of the composite beams.

A method for the analysis of composite beams with web openings that follows the LRFD steel design specifications is considered.

The moment and shear capacities of the composite beams at the web opening were predicted according to this method and compared with the test results.

Main Subjects

Civil Engineering

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305115